In an effort to decrease automobile weight and increase energy efficiency, many automobile manufacturers are employing automobile components that are fabricated from lightweight materials, such as plastic materials (e.g., thermoplastics and thermosets). One such class of plastic materials is generally known as thermoplastic polyolefins (TPO's), such as various grades of polyethylene or polypropylene. Another such class would include ABS and/or ABS/polycarbonate blends.
Some of these components are produced by thermoforming, e.g., vacuum forming, which is generally defined as a process wherein a heated, and thus softened, amount of plastic material (typically in the form of a sheet) is molded into the desired shape through vacuum suction of the warmed plastic onto a pre-formed mold.
Thermoforming can be used for many thicknesses of plastic sheets and can provide great strength in its finished moldings. Fairly complex moldings can be achieved with thermoforming. However, these plastic materials do not typically have a desirable finish (or prematurely lose that finish when exposed to the elements) for use with automotive applications. Furthermore, these plastic materials do not possess sufficient wall thickness. For example, certain conventional automotive components are thermoformed, trimmed and then injection molded.
Various approaches have been taken to providing a high quality automotive paint-like finish to lightweight components, such as molded plastic components. One approach that has received considerable attention uses a surfacing film system having a decorative layer (e.g., a preformed colorant or paint-like film) that can be used to impart a surface effect (e.g., color or other visual pattern) to a thermoformed component. These surfacing film systems are generally referred to as paint or color-containing films. An example of this process can be found in U.S. Pat. No. 5,215,826 to Shimanski et al., the entire specification of which is expressly incorporated herein by reference.
By way of a non-limiting example, paint or color-containing films, especially those used in producing colored automotive components, can be comprised of a decorative layer (e.g., paint, ink, or other colorant), an optional adhesive layer (e.g., a heat-activated adhesive), a preferably scratch resistant optional top clear coat layer, and an optional removable casting base (e.g., a polyester-based sheet). These types of paint or color-containing films are readily commercially available from Avery Dennison Corp. (Pasadena, Calif.), Soliant L.L.C. (Lancaster, S.C.) and Dorrie International (Farmington Hills, Mich.). These paint or color-containing films are generally available in a wide range of colors, including solid metallic colors, and are primarily used in a number of automotive applications.
Additionally, automotive component manufacturers have also used other types of color-containing films, such as mold-in-color (MIC) films. One particular MIC film currently being used is a MIC ionomer film readily commercially available from A. Schulman (Birmingham, Mich.) under the trade name INVISION. The MIC ionomer film typically consists of four discrete layers with a back molded (e.g., injection molded) thermoplastic polyolefin substrate. The layers typically consist of a clear ionomer layer, a colored ionomer layer, an adhesive layer, and a backing layer.
Regardless of the type of paint or color-containing film used, it is sometimes necessary to employ a removable release or masking layer to protect the surface of the component to be thermoformed, due in part to the particular processing parameters encountered during the thermoforming process. This is especially true of thick sheet polyolefin thermoforming. Thick sheet thermoforming typically employs sheets having a thickness in the range of about 0.06 to about 0.5 inches.
Typically, when the thermoforming process is completed, the component is removed from the mold surface and the release layer is then removed. Alternatively, the release layer can be left in place, for example, until the component reaches its final destination, whereupon the release layer can then be removed, thus protecting the outer surface of the component.
An example of decorative laminate composites, and methods for making the same, can be found in commonly assigned U.S. patent application Ser. No. 10/765,427, the entire specification of which is expressly incorporated herein by reference.
Unfortunately, the past history of applications using paint film technology have been somewhat limited in use because of a lack of adequate control of the entire supply chain by one party to manage each production step. As such, conventional paint film technologies have had difficulty being accepted by automotive original equipment manufacturers and Tier 1 suppliers for several reasons.
One reason is that because there are typically numerous separate suppliers and processors within the supply chain of products used to manufacture paint film class A automotive components. Typically, each supplier has a particular expertise limited to specific production steps. As a result, it has been difficult to have each individual supplier take responsibility for scrap loss or component failure when there is a particular quality control issue with either an intermediate or finished component.
When a quality control issue does arise, it usually leads to a breakdown in the relationships among the team of suppliers, as well as the Tier 1 finished component supplier. This breakdown can lead to price increases from the supply chain and difficulties in resolving quality control issues quickly, so that production is not halted due to a lack of material supply.
Accordingly, there exists a need for new and improved methods of producing decorative laminate composites, such as automotive components, including those having paint or color-containing films adhered thereto during the production process.